KVM: ia64: Create inline function kvm_get_itc() to centralize ITC reading.

Move all reading of special register 'AR_ITC' into two functions, one
in the kernel and one in the VMM module. When running on SN2, base the
result on the RTC rather the system ITC, as the ITC isn't
synchronized.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 14a3fabc7d62..ebbd995194fb 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -68,6 +68,16 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
         { NULL }
 };
 
+static unsigned long kvm_get_itc(struct kvm_vcpu *vcpu)
+{
+#if defined(CONFIG_IA64_SGI_SN2) || defined(CONFIG_IA64_GENERIC)
+        if (vcpu->kvm->arch.is_sn2)
+                return rtc_time();
+        else
+#endif
+                return ia64_getreg(_IA64_REG_AR_ITC);
+}
+
 static void kvm_flush_icache(unsigned long start, unsigned long len)
 {
         int l;
@@ -457,7 +467,7 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu)
 
         if (irqchip_in_kernel(vcpu->kvm)) {
 
-                vcpu_now_itc = ia64_getreg(_IA64_REG_AR_ITC) + vcpu->arch.itc_offset;
+                vcpu_now_itc = kvm_get_itc(vcpu) + vcpu->arch.itc_offset;
 
                 if (time_after(vcpu_now_itc, vpd->itm)) {
                         vcpu->arch.timer_check = 1;
@@ -929,7 +939,7 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         RESTORE_REGS(saved_gp);
 
         vcpu->arch.irq_new_pending = 1;
-        vcpu->arch.itc_offset = regs->saved_itc - ia64_getreg(_IA64_REG_AR_ITC);
+        vcpu->arch.itc_offset = regs->saved_itc - kvm_get_itc(vcpu);
         set_bit(KVM_REQ_RESUME, &vcpu->requests);
 
         vcpu_put(vcpu);
@@ -1210,7 +1220,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
                 regs->cr_iip = PALE_RESET_ENTRY;
 
                 /*Initialize itc offset for vcpus*/
-                itc_offset = 0UL - ia64_getreg(_IA64_REG_AR_ITC);
+                itc_offset = 0UL - kvm_get_itc(vcpu);
                 for (i = 0; i < kvm->arch.online_vcpus; i++) {
                         v = (struct kvm_vcpu *)((char *)vcpu +
                                         sizeof(struct kvm_vcpu_data) * i);
@@ -1472,7 +1482,7 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         }
         for (i = 0; i < 4; i++)
                 regs->insvc[i] = vcpu->arch.insvc[i];
-        regs->saved_itc = vcpu->arch.itc_offset + ia64_getreg(_IA64_REG_AR_ITC);
+        regs->saved_itc = vcpu->arch.itc_offset + kvm_get_itc(vcpu);
         SAVE_REGS(xtp);
         SAVE_REGS(metaphysical_rr0);
         SAVE_REGS(metaphysical_rr4);